Here is a Future Card Buddy Fight that i discovered...
When you pick ice climbers change its color to the white costume (Blue one should look white) Now wait 3 seconds and keep on changing the colors untill you meet the same costume (white). So the one you mostly control (Not Nana) should appear white which is normal. Now start a game and then the two ice climbers switch postition.
So the main one will turn to Nana's position and Nana will be the one who you mainly control.
I cant explain very well just try what i said and you will see there would be a switch of color.